I started babysitting now I want to do more and teach them?

[?Love?]

I have 2 5 yr olds, 2 3 yr olds, and a 2 yr old until the afternoon. I want to get on a schedule and just keep things nice and neat because it's been a little hectic the past few days. I try to keep them coloring and stuff, but I want to make it more of a classroom setting and teach them just like pre-k and this will also help my son get ready for kindergarden next year. Any advice would be greatly appreciated. How long should I spend doing schoolwork? They are all hard at listening to me so how to keep them interested? What's appropriate for each age? This will also help me, if I get on a daily schedule I can manage the housework and all that better. Also if you have any websites with worksheets and things that you know of please let me know.